When sleeping in the open air, as when camping, sleeping bags or the like are often used to provide warmth and comfort for the body. However, such devices generally leave all or a portion of the head exposed to cold, drying air. Completely enclosing the head in the sleeping bag reduces fresh air circulation. Prior devices to alleviate this problem have required the use of frames and canvases to construct a head covering, usually integral with a sleeping bag. Such devices provide only limited protection, but significantly add to the bulk and weight of the camper's equipment.
The present invention provides an enclosure for retaining face warmth which is effective, inexpensive, light in weight and easily stored and carried. Several embodiments are provided, each of which utilize an integral, one-piece, generally planar blank of rigid material, such as corrugated paper having a metallized surface on at least one planar side. The blank is cut and scored to provide a plurality of walls which fold toward the metallized surface to form a self-supporting enclosure for a human head. In each embodiment, a rear wall is provided which includes a horizontally central extent approximating the perimeter dimension of a human head and which is tapered from its bottom edge to at least a region above said central extent. The rear wall is hingedly connected along a score line to at least one of the other walls, and further connection is accomplished by interlocking tabs and slots.
In one embodiment, side walls extend from score lines on both sides of a top wall which is connected by the first-mentioned scored line hinge to the rear wall. Tab and slot combinations connect the side walls to the sides of the rear wall to provide a structure which is open at its front and bottom and which is trapezoidal in vertical cross-section.
In another embodiment, two side walls are connected together at their top edges, and to the rear wall along their rear edges, to form a gabled structure which is open at its front and bottom and which is triangular in vertical cross-section.
In another embodiment, the rear wall is formed with a curvilinear taper, a bottom wall is provided, connected by a scored line hinge to the bottom edge of the rear wall, and the opposite ends of a curved roof are connected to the opposite respective sides of the bottom wall. A central, rear edge portion of the roof is connected to the top edge portion of the rear wall to form a structure which is open at its front end and which is semi-circular in vertical cross-section.
Known prior art includes U.S. Pat. Nos. 36,685, 445,049, 615,642, 929,357, 1,257,984, 1,267,551, 2,543,597, 2,555,051, 2,830,305, 2,853,088, 3,045,261 and 3,241,160, Austrian Pat. No. 143,163 and British Pat. Nos. 3,255/1881 and 2,665/1908.